Nuclear Power After Fukushima: IAEA Projections

“It is still an exciting time for nuclear power,” International Atomic Energy Agency (IAEA) Director General Yukiya Amano said last January at a lecture in Singapore. Four years after the devastating accident at Japan’s Fukushima Daiichi nuclear plant, what justifies such a view?

Several objective reasons do.

For many countries, nuclear power remains an important option for improving energy security and reducing the impact of volatile fossil-fuel prices. As a stable, base-load source of electricity in an era of ever-increasing global energy demand, nuclear power complements other energy sources—including renewables.

And because nuclear power, together with hydropower and wind energy, has the lowest life cycle greenhouse gas emissions among all power generation sources, it is crucially linked to mitigating the effects of climate change.

A clear correlation links energy poverty and real poverty. Energy is the engine of development. In his vision for Sustainable Energy for All, UN Secretary General Ban Ki-moon says that “all energy sources and technologies have roles to play in achieving universal access in an economically, socially and environmentally sustainable fashion.” Simply put, to provide energy access to everyone, all forms of energy are needed.

Today, 1.3 billion people have no access to modern forms of energy. One billion people lack proper health care due to energy poverty. And 2.6 billion people, more than a third of the world population, still burn biomass for basic energy needs.


Coupled with concern about securing energy supply and carbon emissions, we get to the current situation: Four years after Fukushima, 30 countries still use nuclear power. About 11% of the world’s electricity comes from 440 operational nuclear reactors. And there are 68 more under construction, with the trend growing.

Speaking of trends: The IAEA’s latest projections from August 2014 show that the world’s nuclear power generating capacity will grow between 8 and 88 % by 2030 (IAEA, 2012). Fukushima may have slowed the growth in nuclear power, but it didn’t stop or reverse it. In short, we expect to see continued expansion in the global use of atomic energy over the next 20 years, especially in Asia, where two-thirds of the reactors currently under construction are being built.

Of the 30 countries that operate nuclear power plants, 13 are either constructing new units or are completing previously suspended construction projects. A further 12 are actively planning to build new units (IAEA, 2014a].


In addition to the 30 established users of nuclear power, about the same number of countries is interested in adding nuclear to its energy mix—the so-called “newcomers.” One thing must be clear: it is the sovereign decision of every country whether to launch a nuclear power program. The IAEA does not try to influence that decision. But when a Member State decides to go that route, the IAEA is there to help (IAEA, 2014a).

The newcomers are at different stages of development: although the majority are currently at the “consideration” stage and have not yet made a national decision, the United Arab Emirates and Belarus are already constructing their first nuclear power plants.

Energy Planning

The future of nuclear power is linked to the future of energy. A country’s energy mix changes over time. Resources that become depleted, too expensive, or environmentally detrimental are replaced by new technologies and energy sources. Hence, energy planning is vital to meeting future capacity needs in ways that are economic, clean, and socially and environmentally responsible.

The IAEA’s energy planning models and tools are used by 130 Member States and by more than 20 regional and international organizations. They assist countries in making informed decisions on future plans, irrespective of their interest in nuclear power.

Fukushima Lessons

Any nuclear power program is a major undertaking. It requires careful planning, preparation and a major investment of time and human resources. Of course, safety, as the Fukushima accident reminded us, is vital to the future development of nuclear power. IAEA Member States responded quickly to the accident by unanimously adopting the IAEA Action Plan on Nuclear Safety (IAEA, 2011) in an effort to look critically at several technical issues in nuclear power production. From severe accident management to communication, from emergency preparedness and response to enhanced research and development, Member States are focusing on lessons learned from the accident to improve nuclear safety in a holistic way.


In addition to post-Fukushima safety upgrades in existing reactors, technological advances are also under way to make nuclear power safer and more efficient. Nuclear fusion, fast reactors and closed fuel cycles can extend the use of our resources to thousands of years. Small and medium-sized reactors (SMR) can respond to issues involving the electricity grid and major capital requirements. There are about 45 innovative SMR concepts, with Argentina, China, India and Russia already building theirs (IAEA, 2014).

The Agency assists its Member States, both newcomers as well as experienced users, in establishing the appropriate legal and regulatory framework, and offers know-how on the construction, commissioning, start-up and safe operation of nuclear reactors. The IAEA also establishes nuclear safety standards and security guidance. Its expert peer review missions help Member States in a wide range of areas, including uranium mining, plant safety, secure nuclear facilities, decommissioning and waste management.

The IAEA, in conclusion, helps nations gain or extend access to nuclear power—one of the great applications of atomic energy. By doing so, the Agency fulfills the mandate it adopted six decades ago: to “seek to accelerate and enlarge the contribution of atomic energy to peace, health and prosperity throughout the world.”[1]

[1]           Article 2 of the IAEA’s statute

References in the Article here.

IAEA Deputy Director General, Head of the Department of Nuclear Energy

Skepticism About a Large Nuclear Expansion in the US

The US may not be good enough at large infrastructure projects to do it well

We are currently in the midst of protracted interest in a “nuclear renaissance,” including newfound support amongst some environmentalists concerned enough about climate change to bracket fears about nuclear waste and risk and argue for a role for nuclear power. There are four modern reactors under construction in the southern US, which if completed would be a significant step forward after 20+ years of no new reactors coming on line. And government-led expansion of Generation III and III+ reactors has been rapid and relatively inexpensive in South Korea and China.

Despite this, I remain skeptical about the US significantly expanding its nuclear generating capacity as a way to mitigate climate change in the next several decades. Specifically, I think that such an expansion would require a large push of funding and leadership from the federal government that would probably have to go beyond a simple price on carbon, and I think that would be a poor investment based on the US’s recent track record with nuclear power plants and other large, complex infrastructure projects.

There are many other possible reasons to think the US shouldn’t make such a push, and some of them partially influence my assessment. Intergenerational ethical problems top many people’s lists, as politically embattled nuclear waste that needs to be contained for thousands of years is not the kindest inheritance. Fears of catastrophic risk including terrorism and weapons proliferation are also prominent concerns, and are near the top of my list. There are also other worries that don’t sway me as much but are significant parts of the public debate, including nuclear exceptionalism, the idea that nuclear contamination is a unique kind of harm to humans and the environment that cannot be traded off against other costs and risks.

These kinds of concerns are enough to make even the highly climate-motivated reluctant about nuclear power, and I think the final deciding factor is the significant uncertainty surrounding how quickly the US could really build new plants, and at what cost, especially when nuclear cost curves appear to be increasing. In fairness, much of this uncertainty comes from experiences with interminable construction delays in the 1980’s that were often the result of escalating regulations during construction, or public opposition in certain parts of the country. The 2005 Energy Policy Act streamlined many of the most problematic aspects of plant licensing, and the four new reactors under construction are in Georgia and South Carolina where the public is largely supportive of nuclear energy, hopefully paving the way for easier construction.

But even these four reactors are already experiencing significant delays and cost overruns. The two AP1000 units at Plant Vogtle began construction in 2013 and have already been delayed until at least 2019. With capital costs nearing $15 billion for 2.22 gigawatt (GW) of capacity, a basic Levelized Cost of Energy (LCOE) calculation suggests a break even price of around $0.14/kWh.[1] The two AP1000 units at the VC Summer Generating Station began construction shortly before Plant Vogtle, and are also delayed from their original 2017-2018 completion time (2017 for the first unit, 2018 for the second) to 2019-2020. Costs have also escalated, from $9.8 billion to at least $11.2 billion. This yields an LCOE estimate around $0.1/kWh.[2] This might also fit into a larger trend of US struggles with large infrastructure projects, including notably more expensive subway construction costs than other countries, and significantly more difficulty planning high-speed rail.[3]

Of course, much time has passed since our last construction of plants, so delays and high costs aren’t totally surprising. Maybe if we committed to building many more AP1000’s in a row, then costs and construction times would eventually come down and yield relatively dispatchable and inexpensive low carbon electricity. A large entity like the US government could afford to make such an investment, but it doesn’t seem like a good bet to me given the alternatives. First, the size and complexity (both engineering and regulatory) of modern nuclear plants along with the long time scales for licensing and construction make learning-by-doing more difficult than for other low carbon generators. The extreme contrast is solar photovoltaics (PV): many 100 MW solar PV arrays are being rapidly installed in several months or less, and PV cells are being manufactured at a fast pace, creating greater economies of scale and allowing for more incremental advances than the nuclear plants that take years to license and at minimum 4 years to build. Furthermore, such large projects as nuclear reactors are almost certainly more likely to experience significant delays, and this is especially true of plants where regulatory scrutiny of any changes during construction is intense and time consuming. Lastly, nuclear reactors are probably the only low carbon generators that could fall completely out of public favor as the result of one discrete event – an act of terrorism, the use of a weapon, or a significant accident could all lead to irreparable reversals of trust by the public and thus the government. While the chance of this happening in any one year is small, if we imagine making a large push for learning-by-doing that could take several decades it starts to be a considerable risk.

This isn’t to say that there will be no new nuclear reactors installed in the US in the future. It’s quite likely that there will be at least several more, and it’s possible that costs could come down significantly after this first new wave of reactors is built and spawn a large, spontaneous build-out. There seems to be a strong possibility that China will expand its nuclear fleet, likely benefiting from a strong centralized government and a track record of timely construction. But it has been a long time since the US has built reactors economically, and relative to other countries we might have a harder time executing large, high profile infrastructure projects, especially if they draw significant public interest and possible litigation. This leads me to believe significant government support would be needed to make nuclear expansion a reality, and that it would not be a wise choice even viewed strictly as a carbon-reduction strategy. Momentum matters when tackling a contentious issue like climate change, and the US might be better off putting its effort behind technologies with cost curves that are more obviously declining, and that can be built in a series of smaller victories rather than large, one-GW steps that could be contentious or frequently delayed.

[1]           See LCOE calculation in Literature Cited section.

[2]          See LCOE calculation in Literature Cited section

[3]           See Lepska (2011) for comparison of per-km costs of subway construction in different cities, and Dayen (2015) for a brief review of the sources of delays and         opposition to high speed rail in California.

Daniel Thorpe is a PhD candidate at Harvard School of Engineering & Applied Sciences. 

References of the Article here.


BEIJING, China - Chinese President Xi Jinping (R) and U.S. President Barack Obama attend a joint press conference in Beijing on Nov. 12, 2014, following their meeting. They agreed to reduce the risk of military conflict and combat climate change. (Kyodo)

Clean Energy Futures and the Role of Nuclear Power

Thanks to a number of factors – natural disasters, the steady flow of increasingly clear and detailed data, and significant new political accords such as the US-China climate consensus from October 2014 – climate change is now very squarely in the public and political debate (The White House, 2014). Many of us, of course, have been arguing that this should have been the case long ago. In my case I am very pleased to have worked as a contributing and then a lead author to the Intergovernmental Panel on Climate Change since the late 1990s’ (IPCC, 2000).

With the scientific consensus now clear that global emissions must be dramatically reduced, by eighty percent or more by 2050, attention is turning to two themes: 1) what is the permissible budget of fossil fuel use? and 2) What are our viable scientific, technological, economic, and political options to power the economy cleanly before mid-century?

On the first question a series of increasingly clear assessments have appeared that document the oversupply we have of carbon-based fuels. In the latest, high-profile paper, researchers Christophe McGlade and Paul Ekins (2015) make clear that Hubbert’s peak – the rise and then decline in a non-renewable resource such as coal, oil or gas – is largely irrelevant to addressing the climate issue. Fossil fuel scarcity will not initiate the necessary transition.

The environmental bottom line is that to meet our climate targets, cumulative carbon dioxide emissions must be less than 870 to 1,240 gigatonnes (109 tons) between 2011 and 2050 if we are to limit global warming to 2 °C above the average global temperature of pre-industrial times. In contrast to that, however, the carbon contained in our global supply of fossil fuels is estimated to be equivalent to about 11,000 Gt of CO2, which means that the implementation of ambitious climate policies would leave large proportions of reserves unexploited.

There have been several recent calls from people and organizations concerned about global warming to use nuclear electricity generation as part of the solution. This includes The New York Times, the Center for Climate and Energy Solutions (formerly the Pew Center on Global Climate Change), and a number of leading scientists, engineers, and politicians. These calls speak to the potential of nuclear energy technologies to deliver large amounts of low-cost energy. New advanced reactors, small-modular reactors, and fusion are all candidates for providing this energy, with knowledgeable and ardent supporters backing each of these technologies and pathways.

At the same time, there are very serious concerns with both the nuclear power industry as it has developed thus far, and with how it might evolve in the future. Alan Robock of Rutgers University summarizes these concerns in an exceptionally clear editorial piece (Robock, 2014), where he questions the ability of the nuclear power industry to meet needed standards of: 1) proliferation resistance; 2) the potential for catastrophic accidents; 3) vulnerability to terrorist attacks; 4) unsafe operations; 5) economic viability; 6) waste disposal; 7) impacts of uranium mining; and 8) life-cycle greenhouse impacts relative to ”renewables.” Battles back and forth between proponents and detractors are sure to continue, but simply looking at #5 on this list alone – the direct costs and opportunity costs of investing in present-day nuclear power–demonstrates the scale of the challenge.

To address this, consider that of the 437 nuclear plants in operation worldwide today, most will need to be replaced in the coming three decades for nuclear power to even retain its current generation capacity, let alone to grow as a major technology path to address climate change. To examine this future, my students Gang He and Anne-Perrine Arvin (2015) and I have built a model of the entire Chinese energy economy, where nuclear power is expected to play a major role.

Today, China’s power sector accounts for 50% of the country’s total greenhouse gas emissions and 12.5% of total global emissions. The transition from the current fossil fuel-dominated electricity supply and delivery system to a sustainable, resource-efficient system will shape how the country, and to a large extent, the world, addresses local pollution and global climate change. While coal is the dominant energy source today, ongoing rapid technological change coupled with strategic national investments in transmission capacity and new nuclear, solar and wind generation demonstrate that China has the capacity to completely alter the trajectory.

The transition to a low-carbon or “circular” economy is, in fact, the official goal of the Chinese government (SI-S2). In the U.S.-China Joint Announcement on Climate Change, China is determined to peak its carbon emission by 2030 and get 20% of its primary energy from non-fossil sources by the same year. The challenge is making good on these objectives. Installed wind capacity, for example, has sustained a remarkable 80% annual growth rate since 2005, putting China far in the lead globally with over 91 gigawatts (4% of national electricity capacity) of installed capacity in 2013 compared to the next two largest deployments, namely 61 gigawatts (GW) in the United States (5% of total electricity) and 34 GW in Germany (15% of total capacity).

China’s solar power installed capacity has also been growing at an unprecedented pace. Its grid-connected installed solar photovoltaic (PV) capacity has reached 19.42 GW by the end of 2013 (1.6% of total capacity), a 20-fold increase of its capacity in four years from 0.9 GW in 2010. These figures show that rapid technological deployment is possible.

Central to this discussion is the role of nuclear power, because half of all the new nuclear power plants planned by 2030 worldwide are forecast to be built in China (roughly 30 of 60 total nuclear plants anticipated to be constructed over the next 15 years).

The question remains whether this large-scale build-out of nuclear power will happen a) in China; and b) as a significant component of the energy mix in other nations, both industrialized and industrializing.

In our modeling work on both the Chinese and United States energy economies (see the program website:, we find that there is a diverse range of pathways that can achieve the needed 80% emission reduction by mid-century. Some are more solar-dominated (Mileva, et al., 2013), some more wind-driven, some heavily reliant on biological carbon capture (Sanchez, et al., 2015) and so forth. A carbon price of $30 – 40 per ton of carbon dioxide is critical to drive each of these cases, and nuclear is no exception.

Returning to the list of challenges that Alan Robock poses, however, the prospects for nuclear power as a major source of energy are troublesome. This path is contingent on solving a very long and serious list of issues that most energy planners would conclude, at least at present, has not been successfully addressed.

Dr. Daniel M. Kammen is a professor in the Energy and Resources Group, and in the Goldmen School of Public Policy, and in the Department of Nuclear Engineering, and is the Founding Director, Renewable and Appropriate Energy Laboratory ( at the University of California, Berkeley.

References in the Article here.

How Does Nuclear Energy Work?: A brief scientific introduction

The basic principle at the core of most nuclear reactors is simple: pack together enough radioactive material of the right type, and you get a chain reaction in which an atom (let’s say uranium) “splits” into two smaller atoms (i.e. undergoes fission), releasing some heat and also some neutrons (particles at the center of atoms); the neutrons can strike nearby uranium atoms and cause them to split as well, leading to a chain reaction that continues to release heat along with the neutrons that sustain it [figure 1, below[1]].

Screen Shot 2015-06-04 at 4.35.30 PM

This splitting happens naturally at a low rate in uranium, so if you pack the material tightly enough with the right conditions, the process can start on its own. In fact it has happened spontaneously in nature on rare occasions, for example 1.7 billion years ago in Oklo, Gabon, the right convergence of natural uranium and water led to an underground “reactor” that lasted for over 1000 years and produced about 100 kilowatts (kW) of heat on average, roughly equal to the output of 20 standard residential rooftop solar arrays in midday sun. Alhough 100 kW is small, the energy that can be released from such a process per unit of fuel is enormous – 1 metric ton of typical enriched uranium fuel can release over 1 billion kWh of thermal energy over its useful life in a reactor, as much as would be derived from 160,000 metric tons of coal.

Building a device that releases this huge store of energy is quite straightforward. Making such a device both safe and economical is the technical challenge engineers and scientists have labored over for the past 60 years. Additionally, engineers must contend with the problem of nuclear waste disposal and how to prevent undesired parties from using the same technology needed for a benign energy system to instead make a weapon. Each of these topics is complex and deserving of multiple textbooks, but here we briefly overview the technical aspects of plant design, fuel cycles, and waste as a primer for reading some of the articles in this review.

Basic Plant Design

At a high level, all a nuclear power plant is doing is carrying out the chain reaction described above in a controlled way, and then using the resultant heat to produce electricity. Typically, electricity is generated by using the heat to produce steam that turns a generator, in much the same way as in a coal plant or concentrating solar power array.

Screen Shot 2015-06-04 at 4.35.40 PM

Figure 2 [above][2] shows a typical modern “Pressurized Water Reactor” (PWR), with three “loops” of water. The first loop passes through the reactor and picks up heat from the chain reaction, but is so pressurized that it does not actually boil. The water pipes carrying this hot water then pass through a steam generator, where water from a separate loop vaporizes to steam. Note that the water coming directly from the reactor core, containing radioactive elements, ideally never comes in physical contact with the water being turned to steam, it just passes its heat along and heads back to the reactor core. The hot steam then turns a turbine to generate electricity, and later comes into contact with pipes from a third loop carrying cold water. The cold water cools down the steam and condenses it back into liquid water, so it can then flow back to the steam generator and be vaporized again. The cooling loop, several steps removed from the actual nuclear reactions, either passes through an iconic cooling tower (like the one displayed on the cover of this publication) or an external water source like the ocean or a river, releasing the heat into the air or water, but not releasing any physical material from the nuclear reaction.

Of course, the details are more complex, especially what is happening inside the reactor itself. All uranium is not equally useful for sustaining a chain reaction – the most abundant isotope, U238, is fairly difficult to use, while the much less common U235 is more desirable. Natural uranium found today contains around 99.3% U238 and just 0.7% U235, which under most conditions is not enough to carry out a chain reaction as neutrons released by the fissioning (splitting) of one U235 atom are not likely to collide with another U235 atom in time. To run most modern nuclear reactors, the uranium either needs to be “enriched,” by increasing the fraction of U235, or needs to be immersed in a strong “moderator,” a substance that makes neutrons bump into other uranium atoms at a higher rate, thus making a chain reaction more likely. Water, the typical working fluid in reactors as described above, is not a very strong moderator, meaning that the uranium has to be slightly enriched in standard plant designs, usually to 3% U235.     However, other configurations are possible – Canada did not want to enrich nuclear material, so instead built the CANDU fleet of plants using deuterium oxide (“heavy water”) which is a much stronger moderator than H2O, allowing even natural uranium to carry out a chain reaction. This eliminated the need for enrichment facilities to increase the fraction of U235 in fuel, but required facilities to produce heavy water instead.


Controlling A Chain Reaction, and Its After-Effects

One obvious question: if a chain reaction is happening in the reactor, releasing ever more heat and neutrons, how do we keep the reaction from “running away” and becoming so hot it melts the reactor? Modern reactors use three main strategies: 1) they are designed with a negative feedback loop, where the reactor becoming hotter slows down the reaction for reasons we will not describe here, 2) they are designed with a “negative void coefficient,” meaning that the reaction slows down or stops if the pressurized water coolant is lost; thus, if the reactor starts to overheat and vaporizes the water, the reaction is slowed or halted, and 3) they use “control rods,” physical rods made of some neutron-absorbing material that can be inserted amongst the fuel rods, absorbing enough neutrons to halt the process. These processes have been very reliable – there have been no major accidents at plants with the above three safety measures.

But there certainly have been accidents at nuclear power plants. They usually involve “decay heat,” which is heat that is released even after the chain reaction has ceased. This heat comes from the continued breakdown of unstable atoms produced in the reaction, and can be of considerable magnitude. A full day after a reaction has been halted, a typical reactor will still be producing 10 Mega Watts (MW) of heat. This is enough to heat all of the water in the “first loop” by over 750 C per day, and would quickly start melting through the reactor vessel and/or start causing explosions if the rest of the loops were not running to draw the heat away. This was the problem at Fukushima – the reaction was halted, but without electricity, the cooling loops could not keep running and the reactor eventually overheated. Managing decay heat is thus one of the central problems addressed in new reactor designs, which brings us to the next section, a brief review of new designs being considered.


Improving Plant Design

So far we have reviewed the predominant type of reactor in the world today, the Pressurized Water Reactor using enriched uranium. There are other types, such as the CANDU reactors with heavy water mentioned before, and “boiling water reactors” that allow the first loop of water to boil rather than keeping it liquid with high pressure. But most of the basic principles are the same. To use nuclear industry parlance, all reactors of these types are usually categorized as Generation III, or III+ if they have slightly improved safety and/or performance.

Do we need to improve on this plant design? In some countries, namely China and South Korea, new Generation III and III+ plants are being built fairly economically (roughly cost-competitive with other options) and are deemed safe enough. In the West, however, most countries either deem them unsafe or struggle to build them economically, for a variety of reasons.

Especially given growing interest in low-carbon electricity, much attention is being given to new reactor and plant designs. These are too varied and detailed to treat in depth, but they usually involve some of the following three: 1) improved safety, 2) reduced cost, and 3) reduced waste.

“Passively safe” is a term associated with next-generation plant designs, ideally meaning a plant design where decay heat is handled passively and does not rely on active engineering systems that could fail. A simple example would be to have the reactor resting in a huge pool of coolant all the time, so large that even in the event of indefinite power outage the coolant reservoir is able to handle the decay heat. Costs can be reduced by reducing the complexity of plant design, or by operating at higher temperatures to allow better thermal efficiency in electricity generation. Wastes can be reduced in several ways, such as by modifying the nuclear chain reaction to produce less stable radioactive byproducts, resulting in less total waste with shorter lifetimes.

Some proposed designs attempt to combine multiple improvements, for example small modular reactors (<300 MW) could be significantly safer due to their small size and easier thermal management, and could reduce costs by being easier to assemble in factories with less time for costly on-site construction. Of course, only time and experience will tell if their costs would actually be lower, or whether smaller economies of scale or other factors would make them more expensive.   Most proposed designs trade off between safety, cost, or wastes, for example “fast neutron reactors” can significantly cut waste generation but are usually more costly, or supercritical water reactors that could reduce costs but may not offer much additional inherent safety. But all of these designs are very far from commercial licensing, probably on the order of a decade or longer, and significant financial investment and patience will be required to develop them further and determine with more certainty if any offer a more appealing set of traits than current Generation III reactors.

Fuel Cycle

In the final section of this brief overview, we will examine the basics of the nuclear fuel cycle as it exists in most countries with PWR’s. Natural uranium is mined and sent to a fuel enrichment and fabrication facility. There it is separated into two streams – one enriched in U235, usually to around 3%, and another very depleted in U235, which is usually discarded. Unfortunately, the same equipment used to enrich the uranium to this level for nuclear power can also be used to enrich it further, closer to 90% U235, to make weapons-grade material, leading to ambiguities over whether some countries are enriching uranium for civilian or military purposes.

The enriched fuel can then be used in PWR’s, where it serves as fuel until the level of fissionable isotopes becomes very low again. Notice that the spent fuel leaving the plant now has quite a variety of radioactive products, formed through various reactions happening inside the reactor. The diversity of these wastes adds to the challenge of waste management, as some have half-lives of only several years while others have half-lives of many thousands of years.

Also notice that the spent fuel contains a significant amount of plutonium. This plutonium could also be used as fissionable material in a reactor, so many countries choose to “reprocess” their waste by extracting the plutonium and mixing it with depleted uranium to make more reactor fuel. This process tends to reduce the volume of waste and could be advantageous if uranium were in short supply or expensive, but for now uranium seems relatively abundant and inexpensive, and the reprocessing itself has proven expensive. Pure, fissionable plutonium created through reprocessing also leads to concerns about safety, weapons proliferation, and terrorism. However, despite these concerns, most countries using nuclear energy routinely reprocess their fuel, with the US being a notable exception mostly due its policies that attempted to “lead by example” in reducing weapons proliferation in the 1970’s.

As with plant designs, there are ways to improve on the current fuel cycle. One high level improvement would be to form a “closed” rather than “open” fuel cycle by utilizing different kinds of reactors that generate as much fissionable materials as they consume. Another is to use “fast reactors,” described earlier, to reduce the amount and lifetime of wastes. There are also possible geopolitical improvements, for example a global fuel cycle where a few agreed-upon countries supply fuel and accept waste from other countries. This would allow some countries to have nuclear power plants while never enriching fuel or handling their waste, and for countries like the US to have an easier waste disposal solution. Like the new reactor designs, though, these changes would take a very long time, easily beyond a decade, so if countries or the world decide they are desirable they will require patience.

[1]           Source: Intel Education Resources.


[2]           Source: US National Nuclear Regulatory Commission.



LEED at University Residential Sites: Impact Analysis

Introduction and Overview of LEED

In the 21st century, sustainable development, or maintaining the ability to provide for current needs without compromising the ability to meet future needs, is a primary concern (United Nations). In order to achieve sustainable development, the performance of the built environment must be dramatically improved through more effective energy use without compromising indoor air quality. One prominent effort to promote a high performance built environment is the Leadership in Energy and Environmental Design (LEED) green building accreditation system developed by the United States Green Building Council, USGBC. LEED is a comprehensive system of standards that seeks to promote “buildings and communities [that] will regenerate and sustain the health and vitality of all life within a generation” by defining the characteristics of a sustainable built site (USBGC). Under LEED, a recognized sustainable built site is awarded one of four levels of LEED accreditation: Certified, Silver, Gold, or Platinum.

This study will evaluate the effectiveness of the LEED standard as a vehicle for indicating high performance residential sites at universities. One LEED Silver accredited site and 14 non-accredited sites are evaluated in this study based on three metrics: utility costs per permanent occupant, land affected per permanent occupant, and greenhouse gas emissions per permanent occupant. As the findings will illustrate, lower utility costs and CO2 emissions of the LEED Silver accredited site serve as positive indicators regarding the effectiveness of the LEED rating system, while the land area impacted per permanent occupant by the LEED accredited site is not significantly better the than non-accredited sites. This shortcoming also provides lessons for sustainable building using the LEED system of standards.

Criticism: How effective are LEED Standards?

Since its introduction, some experts have questioned the effectiveness of the LEED system. Important criticism comes from Harvey Bryan, a professor at Arizona State University who was active in the development of ASHRAE 90.1 Appendix G, a universally accepted energy efficiency standard also used to assess projects for the LEED accreditation. Bryan notes that LEED assesses a built site’s performance through modeling the energy use of two structurally identical versions of the site in accordance with ASHRAE 90.1 Appendix G standard (2009, 175). The first version provides a baseline for site performance—if the site was constructed as a “typical” site of the same type. The second version models the site exactly as it will be built. The difference is used for awarding credits toward LEED recognition. According to Bryan, project teams sometimes choose to model an abnormally low performance site for the baseline, dramatically inflating the modeled performance of the project (LEED, 70). In one case, the Biodesign Institute, a LEED Gold accredited project at Arizona State University modeled 60% energy savings, but only realized 21% savings (LEED, 70).

Evaluation: Comparative Performance of LEED Accredited

Versus Non-LEED Accredited Residential Sites

  To assess the effectiveness of the LEED system, the data from these 15 residential sites was compiled and evaluated.

Site Name Number of Occupants Usable Square Feet
Canaday Hall 246 56139
Grays Hall 98 25184
Greenough Hall 83 22297
Hollis Hall 60 18814
Holworthy Hall 84 18827
Hurlbut Hall 58 17335
Lionel Hall 34 8392
Matthews Hall 152 43583
Mower Hall 34 8392
Pennypacker Hall 103 25695
Stoughton Hall 57 19265
Straus Hall 95 22097
Thayer Hall(LEED Silver Accredited) 157 44630
Weld Hall 153 36213
Wigglesworth Hall 202 49274


The 15 sites are assessed on three different metrics:[2]

  1. Annual utility cost per permanent occupant
  2. Annual greenhouse gas emissions (GHG) per permanent occupant
  3. Annual land area affected per permanent occupant

Thayer Hall received LEED Sliver accreditation in 2011, so all measurement are based on averages from FY2012, FY2013, and FY2014.[3]


To evaluate the performance of each site, utility usage and cost data were acquired using Interval Data Systems’ Energy Witness reporting tool. Unless noted otherwise, all years referenced in this study are Harvard fiscal years. Thayer Hall received its LEED Silver accreditation in July of calendar year 2011, so the data includes fiscal years after accreditation, FY2012, FY2013, and FY2014. The results are an average of FY2012, FY2013 and FY2014 usage and cost data. Averaging three years eliminates abnormalities caused by random short-term fluctuations in usage. The most resource intensive dorm amenities, laundry and irrigation are not distributed evenly among the 15 dorms. Therefore, to allow for a valid comparison, this difference was mitigated by assessing electricity and water consumption of sites with laundry facilities and sites without, then adjusting for usage based on population data and facility distribution. Water and sewage consumption values in this study exclude site irrigation. The GHG emission metric accounts for both utility consumption and the mix of fuels in production. Metrics are calculated on a per occupant basis to allow direct comparison between sites that would otherwise be impossible to compare because the 15 sites are of different sizes and house different numbers of occupants.

Metric: Annual Utility Cost

Annual utility costs provide insight into the economic validity of LEED. USGBC claims that sites with LEED accreditation have lower utility costs than equivalent non-LEED sites. If the LEED accreditation system is valid, then sites granted any level of accreditation should have substantially lower utility costs per occupant then sites without accreditation.

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Figure 1

From FY2012-FY2014, LEED Silver accredited Thayer Hall was the third most efficient site, surpassed only by Straus Hall and Weld Hall. Thayer Hall operates at a cost of $95.66/occupant less than the average of the 14 other sites, a 16.3% advantage. Thayer has 157 occupants. In this instance, over $15,000 per year is saved by constructing to LEED’s standards. This demonstrates that LEED can make buildings more cost effective, as claimed.

Metric: Annual Greenhouse Gas Emissions

  Site performance should also be evaluated based on GHG emissions because they provide more complete information about the performance of a site’s fuel mix than utility cost alone, considering that utility cost could be lower due to reliance on cheap, CO2 intensive fuels. The USGBC claims that LEED accredited buildings will emit less CO2 than equivalent sites without accreditation.

GHG emissions for all 15 sites in this study have three sources: electricity consumption from the New England electric grid (eGRID sub region NPCC New England), natural gas consumption, and steam consumption. All fuel emission factors are from the Energy Information Administration. GHG emissions from steam production are adjusted to account for secondary electricity production through Harvard’s district heating system. The results are as follows:

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Figure 2

Thayer Hall emits 1,617 lbs CO2/year per occupant less than the average of the 14 other sites, an 18.1% difference. This indicates that LEED accredited residential sites emit significantly less greenhouse gases per occupant than sites without accreditation. This supports the conclusion that LEED is a valuable tool for certifying low CO2 residential sites in university environments. This is valuable since GHG emissions are understood to be disruptive to global climate systems and many universities face significant pressure from within and without to dramatically reduce their GHG emissions. This metric indicates that constructing built sites to comply with the LEED rating system is an effective strategy for universities to respond to the pressure to reduce GHG emissions.


Metric: Land Impact

Built sites also affect land use patterns through energy consumption, producing a “land footprint.” Some cheap and low CO2 energy sources, such as biomass or natural gasderived electricity, have huge land impacts (McDonald). This contributes to food shortages, biodiversity loss, and habitat destruction. As a result, a sustainable built site will optimize its energy mix to impact as small an area as possible while minimizing GHG emissions. In assessing land use, water and sewer usage are assumed to have a negligible impact on land use.

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Figure 3

Thayer Hall’s land use per occupant is the 7th lowest out of the 15 sites assessed and only 1.6 % below the 14-site average. Therefore, the LEED Silver accredited Thayer Hall does not perform as favorably by this metric as it did with utility usage or greenhouse gas emissions.   Thayer Hall’s poor performance is a direct result of the fact that electric power consumption is the most land intensive of all three energy utilities measured, accounting for an average of 65% of land impact across all 15 sites, but only 29.8% of energy consumption. Thayer Hall draws 40.1% of its total energy consumption in the form of electric power, which is more than any other site. Its reliance on electric power accounts for its high land area impacted, a direct consequence of the fact that Massachusetts derives 46% of electric power from land intensive natural gas (2014, 13).

Summary of Metrics and Conclusion

Unfortunately, limitations on available data limited the scope of this study to one LEED accredited site. Additionally, all of the sites studied are located in the city of Cambridge, MA, which has adopted local building energy codes that may be more or less stringent that those used in other localities. This suggests that further research is necessary before any broad conclusions can be made. However, utility costs, greenhouse gas emissions and land impact indicates that the LEED system provides advantageous standards for constructing sites with reduced utility costs and reduced GHG emissions. But the site land impact results suggest that LEED may not enhance site performance on significant metrics that fall outside of its immediate scope, such as land area impacted. Therefore, LEED is a useful tool for developing a sustainable built environment, but institutions that utilize the LEED system should do so with an actively clear vision regarding built site performance, as LEED is not inclusive of every relevant metric of a high performance built environment. As a result, the LEED system is still valuable, butthe construction of sustainable environments requires careful diligence in addition to using the LEED system.

Clifford Goertemiller is an undergraduate at Harvard.

[2] A note on transparency: All data used in this study is available on Harvard’s Energy Witness tool.

[3] The Harvard fiscal year runs from July 1st to June 30th

References of the Article here.

Making climate change meaningful: celebrity vegans and the cultural politics of meat and dairy consumption

The disconnection between what we know about climate change, and how we relate this to the cultural values of our everyday lives, is a gap that needs addressing if we are to deal with this issue in a meaningful and effective way (Doyle 2011a; Corner, Markowitz and Pidgeon 2014). Climate impacts across the globe are becoming increasingly visible and felt, but for those living in the north and western hemisphere, climate change can still feel a distant and remote issue if not experienced directly (Pidgeon 2012; Harvey 2015), with seemingly little connection to the social practices and concerns of our daily lives. Yet, climate change is intimately bound up with our daily activities, from the food that we purchase and the transport we take, to the products we buy and the values we hold. Creating more sustainable societies requires significant changes to our energy intensive lifestyles. But how do we achieve this?

Connecting climate to culture is essential (Doyle 2011a; Hulme 2015). Making climate culturally meaningful involves creating linkages not only between what we do and how this affects our climate, but also using culture (through popular music, arts, literature, media, entertainment and sport) as a way of inspiring and helping achieve social and political change. From this perspective, the dominance of celebrity culture within our media and cultural landscape means that celebrities have an increasing role to play in the cultural politics of climate. Indeed, a growing number of scholars are focusing critical attention upon celebrity involvement in environmental and humanitarian activism (Brockington 2008; Littler 2008; Boykoff and Goodman 2009; Anderson 2013).

Celebrities can help draw attention to an issue and galvanise youth engagement (Alexander 2013). At the same time, the individualisation and commodity relations which support the societal processes of celebritization (Driessens 2013) can be problematic in the context of climate change, which requires significant socio-economic shifts to achieve sustainable societies. Yet, given the disconnect between climate science and the social practices of the everyday, celebrities can act as important intermediaries to help make the complexities of climate change more accessible and relevant to our daily lives. Food is one such area where celebrities can help link the impacts of climate change to our consumption habits. Indeed, as one of the largest contributors to greenhouse gas emissions, the production and consumption of meat and dairy (Gerber et. al 2013), is a crucial social practice that requires further interrogation.

The climate politics of meat and dairy consumption

According to the Food and Agriculture Organization of the United Nations (FAO) meat and dairy consumption contributes 14.5% of human induced global greenhouse gas emissions (Gerber et. al 2013). This report builds upon FAO’s 2006 publication, Livestock’s Long Shadow, which brought significant attention to the climate impacts of the livestock sector. Emissions are produced through land use for livestock pastures and animal feedcrops, leading to significant deforestation; methane via animal effluence; nitrous oxide via animal waste, and water use for the irrigation of animal feed crops, particularly soy beans (FAO 2006). In 2006, the FAO stated that ‘civil society seems to have an inadequate understanding of the scope of the problem’ (FAO 2006, 282).

NGOs have been reticent to engage with this issue for fear of alienating people and for addressing what is perceived to be too personal an issue – the food that we eat (Doyle 2011b, Laestadius 2014). Prominent environmentalists such as Bill McKibben have further contributed to a general reticence within civil society to tackle this issue (McKibben 2010). Likewise, governments have been disinclined to promote the reduction or elimination of meat and dairy because they are generally ‘reluctant to tackle questions of personal choice and consumption’, instead focusing their climate campaigning efforts upon household energy consumption (Robins and Roberts 2006, 39).

This failure to adequately address the climate impacts of meat and dairy illustrates how forms of consumption are embedded within existing socio-cultural practices: meat and dairy consumption is largely conceived as a ‘natural’ practice within western, and middle-class, societies (Heinz and Lee 1998). Lack of engagement by NGOs and governments thus means that the opportunity to link climate to the practices and values of everyday life (even when this involves questioning those values and practices) is significantly reduced.

The celebrity politics of veganism

Despite this failure to engage, the recent rise in the number and profile of celebrity vegans, that is, celebrities from the fields of entertainment, sport and politics who have publically adopted a vegan diet (CBS News 2011) –involving the elimination of meat, dairy, eggs and fish – offers the potential for a previously stigmatised practice (Greenebaum 2012) to achieve mainstream credibility. Forbes announced ‘high-end vegan cuisine’ as one of the Top Ten food trends of 2013 (Bender, 2013). Historically, veganism has been largely viewed in a derogatory way, framed in mainstream media as ridiculous and ‘difficult’, with vegans characterised as ‘oversensitive’, ‘ascetic’ and ‘hostile’ (Cole and Morgan, 2011,139). The increasing visibility of vegan celebrities is thus welcome, bringing an ignored or stigmatised identity (Greenebaum, 2012) into mainstream media culture.1

In order to consider the potential influence of celebrity vegans, it is important to understand their different celebrity profiles. For example, the actor and writer, Alicia Silverstone, most famous for her role in the film Clueless (1995), and comedian and TV entertainer/talkshow host, Ellen DeGeneres, are two prominent female celebrity vegans who use their celebrity status to promote veganism – through books (specifically Silverstone), television interviews, websites and social media. Both are celebrities within the entertainment industry, but present very different approaches to communicating their veganism, and their own vegan philosophy.

Silverstone’s veganism is communicated through her book, The Kind Diet: A Simple Guide to Feeling Great, Losing Weight, and Saving the Planet (2009), which is accompanied by an environmental lifestyle website/blog called The Kind Life, and supported by a Facebook page and Twitter feed (The Kind Life, 2014). As part of The Kind Life brand, the books, website and social media presence work as an integrated platform to promote Silverstone’s personal vegan lifestyle and philosophy. Utilising discourses of self-help and healing, Silverstone places the self as central to veganism, where being kind to oneself and others is the route and basis to becoming vegan.

Historically, animal suffering and anti-speciesism (against distinctions between humans and animals) are the political and ethical basis of veganism (Adams 2010; Cole and Morgan 2011). Silverstone also adheres to this: ‘The dairy industry is, in a word, cruel: That is why I gave up dairy in the first place’ (2009, 42). Silverstone’s vegan ethics, however, are human centred. Discussing why meat and dairy is ‘nasty,’ Silverstone argues that these harm the health of your body, then discusses their impacts on animals, and then the planet.

Silverstone’s Kind Life brand positions veganism through a framework of compassion, care and emotion; an important component of a vegan ecological ethic (Plumwood 2002; Adams 2010). Silverstone makes valuable interconnections between humans, animals and environment, particularly important for an understanding of climate change. Yet, the personalized lifestyle presented by Silverstone – such as shopping choices and socializing with celebrity friends – draws upon and extends her celebrity commodity status, making it difficult to disentangle the political and ethical from the individualized commodity lifestyle of celebrity culture.

Since 2003, Ellen DeGeneres’ – the 5th most powerful celebrity of 2013 (Forbes 2013) –has hosted her daytime talk show, The Ellen DeGeneres Show, where her affable, warm and empathetic persona has made her a mainstream success. Yet, DeGeneres career was significantly affected when she came out as a lesbian in 1997, causing a 3year hiatus in her career. In 2008 she became vegan and had a high profile vegan wedding with actor, Portia De Rossi, which reinforced her celebrity status. DeGeneres’ migrated into vegan lifestyling in 2011 with the launch of her website, Going Vegan with Ellen (Pollack, 2011), which has since been subsumed into a section called ‘Ellen’s Healthy Living’ on the Ellen DeGeneres Show website.

Whereas Silverstone’s vegan message is consistent across all media platforms, DeGeneres’ veganism represents only a part of her celebrity profile. On her website, veganism is presented primarily through discourses of health – ‘Going vegan increases your metabolism, so even if your calories increase, you won’t necessarily be gaining weight’ (Ellen DeGeneres Show, 2014) – and to a lesser extent animal welfare. DeGeneres deploys other celebrity vegans to communicate her message: images of ‘Famous Vegans’ from entertainment, sports and politics appear with descriptions next to each ranging from health and weight loss benefits, animal rights, and to a much lesser extent, environmental concerns. The integration of other celebrities within the promotion of veganism is a strategy that contributes to the celebritization of this issue, increasing the potential reach and accessibility of veganism, yet further inscribing this within celebrity commodity relations (Driessens 2013).

Although it is through a celebrity public self that DeGeneres’ veganism is situated, a private self is revealed in an interview with journalist, Katie Couric (CBS News 2010). DeGeneres explains her veganism as an expression of the need for love, compassion and equality for all humans and species, thus revealing a more radical vegan ethic than is communicated via her talkshow and website. Yet it is through her talkshow that DeGeneres is able to present her beliefs and values in a humorous and non threatening way. DeGeneres has a staggering 29.7 million twitter followers (Silverstone has 249,000). Her tweets replicate the humorous and caring public self of her TV show and website – combining jokes, celebrity promotions, excerpts from her TV show, social and political issues (such as anti-bullying and LGBT equality) and funny/cute animal stories. It is through this relationship with her audience that a consideration of the effects of DeGeneres’ veganism thus needs to be undertaken.

Climate, culture and celebrity

Making climate culturally meaningful is an urgent matter. Celebrities can help by relating the causes and impacts of climate change to existing socio-cultural practices, facilitating not only a questioning of cultural values (such as meat and dairy consumption) but simultaneously making the necessary changes to our habits appear more positive, achievable and accessible. Yet, we must also be mindful of questioning the individualist aspirational lifestyle that accompanies celebrity culture, and be attendant to the range of possibilities for meaningful and wide scale socio-cultural changes necessary for addressing climate change.


Julie Doyle is a Reader in Media at the University of Brighton, UK. She is on the Board of Directors of the International Environmental Communication Association (IECA) and a co-founder of the Science and Environment Communication Section of the European Communication and Research Education Association (ECREA).

References cited here.

1 A more detailed analysis of celebrity vegans is presented in my forthcoming article, ‘The politics of being vegan: celebrities, ethics, ecology and feminism’, Environmental Communication, Special issue: Spectacular Environmentalisms (2015).